//
/***********************************************************
             File name:      main.c
             Author:         Bitat (陆叁柒)
             Email :         Bitat@qq.com
             Gitee :         https://gitee.com/bitat
             CSDN  :         https://blog.csdn.net/bitat 
             History:        2023/2/7
************************************************************/
    

#include <stdio.h>

int main()
{
    int i = 0;
    int sum = 0;
    int input = 0;
    printf("请输入一个整数:>");
    scanf("%d",&input);
    for(i = 21; i < input+21; i++)
    {
        sum +=i;
    }
    printf("结果为:%d\n",sum);
    return 0;
}
